In 1967 the Commission Sportive International decided to change the regulations for Group 6 prototypes competing for the World Sportscar Championship. Instead of competing cars having unlimited engine capacity, such as the Ford Gt40 Mk.IV that had a 7.0-litre engine, the CSI announced a 3.0-litre engine displacement cap for the prototype class for 1968. Well aware that few manufacturers were ready to take up the challenge, the CSI also allowed 5.0-litre Group 5 Sports Cars, of which a minimum of 25 units had to be manufactured to participate.
Starting in July 1968, under the leadership of Ferdinand Piëch, Porsche committed to take advantage of the new Group 5 rules and started working on a new prototype car based on the company’s previous Porsche 908 sportscar prototype racer. Time was short, as the 1969 24 Hours of Le Mans was just nine months away. On April 20 Piëch displayed 25 917s parked in front of the Porsche factory to stunned CSI inspectors. They fit the Sportscar regulations perfectly with two seats, a luggage compartment, spare tire and the ability to be licensed for street use, which included turn signals, turn-key ignition, and a horn.
The new car designed by Hanz Mezger was built using an ultra-light spaceframe chassis that weight just 42kg and was permanently pressurised with gas so that even the minutest of cracks could be detected. While during the lifeline of the Porsche 917, the engine saw an increase in displacement of upto 5.4-litre with twin turbocharging that would take the power up to an incredible 1580 horsepower, the first lot of Porsche 917 featured a 4.5-litre naturally-aspirated flat-12 cylinder unit that produced a relatively modest 520bhp in 1969.
Ex-Aston Martin team manager, John Wyer’s racing team J.W. Automotive became Porsche’s Werks team for 1970. After securing a sponsorship from Gulf Oil, the team created a new wedge shape tail of the Porsche 917K that aided with the much needed stability over the original 1969 car.The new tail transformed the car and the Gulf Porsche team dominated in 1970 and 1971 winning the World Championship for Porsche both years. Armed with a sponsor and two brand new Porsche 917K cars, J.W.Automotive began their 1970 season of the World Sportscar Championship.
This here is the very same Gulf Porsche 917K, Chassis no. 917-015 which won the first race in the 1970 World Supercar Championship at the 24 hours of Daytona. It was here that the Group 5 Porsche 917 and the Ferrari 512S would meet for the first time in contention for the world championship title.
At the 3.8-mile circuit at the Daytona International Speedway, J.W.Automotive’s two Porsche 917Ks dominated the race finishing 1-2, ahead of the Ferrari 512S driven by Mario Andretti, Arturo Merzario and Jacky Ickx. This very Porsche 917-015 piloted by Pedro Rodriguez, Leo Kinnunen and Brian Redman finished first, winning the 24 hour event with an astonishing margin of 45 laps, the largest margin victory in the history of the legendary endurance race. 724 laps and 2759 miles (4440km) is what it took for the Porsche 917K to be branded as the titan of the endurance racing world for the very first time. After this first victory at Daytona, the Porsche 917 would go on to win the 24 Hours of Le Mans for the very first time, and eventually the 1970 World Sportscar Championship.
As for Chassis no. 917-015, the domination would continue into the 1971 season. It would be raced as a Spyder after being officially converted by the Porsche factory, going on to win the 1971 Interserie Championship. In 2000 the 917-015 was restored to its original 1970 24 Hours of Daytona specification and it currently resides at the Canepa Museum in Scotts Valley, California.